Method and apparatus for mixing contained liquids



June 18, 1968 A. E. OGREN ETAL 3,333,895

METHOD AND APPARATUS FOR MIXING CONTAINED LIQUIDS Filed Aug. 17. 1966 3 Sheets-Sheet l INVENTORS AXEL E. OGREN VICTOR M. WILLIS B MIL-L2 Anonusxs June 18, 1968 A. E. OGREN 'ETAL METHOD AND APPARATUS FOR MIXING CONTAINED LIQUIDS 3 Sheets-Sheet 2 Filed Aug. 17. 1966 INVENTORS AXEL E.OGREN VICTOR M. WILLIS 312 ATTORNEYS FIG.2

June 8, 1968 A. E. OGREN ETAL 3,388,395

METHOD AND APPARATUS FOR MIXING CONTAINED LIQUIDS Filed Aug. 17. 1966 3 Sheets-Sheet 3 FIG.3

INVENTORS AXEL E. OGREN VICTOR M. WILLIS ATIOBNEYS.

United States Patent 3,388,895 METHOD AND APPARATUS FOR MIXING CONTAINED LIQUIDS Axel E. ()gren, Mayfield Heights, Ohio, and Victor M. Willis, Dolton, Ill., assignors to The Sherwin-Williams Company, Cleveland, Ohio, a corporation of Ohio Filed Aug. 17, 1966, Ser. No. 572,954 8 Claims. (Cl. 259-75) ABSTRACT OF THE DISCLOSURE A liquid mixing method and apparatus for mixing liquids within a closed cylindrical container by repeatedly oscillating the container through an arc of at least 90 degrees about an axis which passes through the container and its contents.

This invention relates to methods and apparatus for agitating or mixing and, more particularly, to methods and apparatus for agitating liquids, such as paints contained in cans, to uniformly disperse solids which may have settled in the cans and/or to uniformly disperse an added colorant throughout the paint.

Many paint agitating machines in use today were designed to agitate paint contained in a can primarily to break up and disperse settled and agglomerated pigment cakes or masses in the bottom of the can. Such agitating machines have, therefore, been designed to perform this function and agitate the paint by reciprocating the can in a direction which substantially corresponds to the axis of the can. Although these prior art agitators usually disperse the agglomerated pigment throughout the liquid, problems arise when such agitators are employed to disperse an added colorant throughout a base paint.

In order to accomplish the tinting of paint with such agitators, it has been necessary to remove some of the paint from the can prior to adding the colorant, since the above-described motion of these prior art agitating machines produces a jarring and splashing of the paint in order to break up pigment agglomerates, and this jarring and splashing of the paint does not effectively mix a colorant in the paint in a reasonable time period. The inability of a paint agitating or mixing machine to effectively mix an added colorant in a paint is more significant today than the machines ability to break up and disperse pigment agglomerates, since many paints which are sold today are latex paints which do not have hard settlings. Moreover, the wide range of paint colors required today for home and commercial applications necessitates the use of added tinting colorants in a base paint.

The agitating motion required to effect the dispersion of settled pigment agglomerates is not only ineffective to disperse an added colorant in a paint in a reasonable amount of time, but produces serious vibration problems in the agitating machine.

The present invention overcomes many of these prior art diiliculties by providing a machine which will effectively disperse an added colorant in a paint and at the same time break up and disperse any pigment agglomerates that may have settled from the paint. The present invention provides a machine which oscillates a paint can about an axis perpendicular to the cylindrical axis of the paint can, such oscillation being through an are 'ice of about degrees or more. Desirably, the oscillation axis may pass through the center of gravity of the can. This motion produces considerable turbulence within the can because of the irregular shape of the can about the above-described axis of oscillation. Since mixing and dispersing are accomplished by turbulent flow rather than by jarring and splashing, the can requires little or no outage prior to a tinting operation. Moreover, the mixing and agitating motion produced by the machine according to this invention results in a completely homogeneous mixture in less time and with fewer cycles per minute. The machine therefore, requires less power and is more economical to operate.

A general object of the present invention is to provide fluid mixing and agitating methods and apparatus which overcome many of the previously described prior art problems.

A more specific object of the present invention is to provide a paint mixing and agitating device which effectively disperses both added colorants and pigment agglomerates in the paint by creating turbulent flow in the paint.

A further object of the present invention is to provide a paint mixing and agitating apparatus which disperses colorant in a paint in a relatively shorter time and which requires fewer cycles per minute and, therefore, less power to accomplish this result, with a resultant overall economy.

A further object of this invention is to provide a paint agitating and mixing device which minimizes the vibrations inherent in all such devices.

A still further object of this invention is to provide a paint mixing and agitating device which has an improved can clamping means which will retain a variety of can sizes.

Another object of this invention is to provide a method for mixing and agitating a liquid in a closed cylindrical container comprising oscillating the container repeatedly through an arc of at least about 90 degrees about an axis passing through the container and its contents and perpendicular to the cylindrical axis of the container.

Yet another object of this invention is to provide a paint mixing and agitating machine having a simple and compact design with improved balance and weight distribution and which may be easily moved from place to place.

These and other objects, features, and advantages of the invention will become more apparent and more easily understood from the following detailed description and from the accompanying drawings.

In the drawings:

FIG. 1 is a perspective view of a paint mixing and agitating machine according to this invention, with the front panel of the machine removed to show details of construction;

FIG. 2 is a front elevational view of the machine illustrated in FIG. 1, with portions of the machine broken away for clarity and illustrating the drive shaft rotated 270 degrees in a clockwise direction from the position illustrated in FIG. 1;

FIG. 3 is a fragmentary, side elevational view of the apparatus, with portions broken away for clarity, the plane of the view being indicated by the line 33 in FIG. 2;

FIG. 4 is a plan view of the container clamping assembly portion of the apparatus;

FIG. 5 is a cross sectional view of the container clamping assembly, the plane of the figure being indicated by the line 5--5 in FIG. 4; and

FIGS. 6 through 9 are schematic illustrations of the drive linkage, each figure illustrating a different linkage position during one agitating cycle.

, Referring now to the drawings, a paint agitating and mixing apparatus 10 is illustrated. The apparatus 10 comprises a top plate 11 on which a pair of spaced side frame members and 21 are mounted. The side frame members 20 and 21 are joined by a frame support 22 and by a pair of carriage bolts 23 which are surrounded by spacer tubes 24. Hangers 25 are provided at the ends of the carriage bolts 23, and the hangers support a motor mounting plate 26. The mounting plate 26 supports a drive motor 27. The drive motor-'27 and the mounting plate 26 extend through apertures 28 and 29 which are respectively provided in the frame members 20 and 21.

The drive motor 27 (FIG. 3) has a drive shaft 30 upon which a flywheel 31 and a pulley 32 are mounted. The pulley 32 drives a drive pulley 33 by a V-be1t 34. The drive pulley 33 is keyed to a drive shaft 35, and the drive shaft 35 is rotatably mounted between the side frame members 20 and 21 by bearing assemblies 36 and 37 respectively.

One end of the drive shaft 35 projects through the side frame member 21 and is fixed to a counterbalanced crank arm 38. One end of the crank arm 38 is provided with a bearing pin 39 which projects outwardly from the crank arm. The bearing pin 39 has a reduced end portion 40 upon which a pair of connecting rods 41 and 42 are pivotally mounted, preferably by roller bearings, and retained by a snap ring 43. There is provided a suitable spacer such as a nylon washer 44 on the reduced end portion 40 of the crank arm 38 and between roller bearings carried by the connecting rods 41 and 42 so as to separate 7 these hearings on the reduced end portion 40.

The other ends of the connecting rods 41 and 42 are respectively provided with ball bearing assemblies 45 and 46, and the inner races of the bearing assemblies 45 and 46 are respectively connected to bearing pins 47 and 48.

The bearing pins 47 and 48 respectively extend through arcuately cut channels 49 and 50 in the side frame member 21. The channels 49 and 50 define arcuate travel paths for the bearing pins 47 and 48 so that the axes of those pins travel in arcuate paths of 90 degrees or more during each 180 degrees of rotation of the drive shaft 35. Thus, the effective length of the crank arm (the distance between the axis of the drive shaft 35 and the axis of the bearing pin 39) is one-half the length of the identical chords of the 90-degree arcs traversed by the axes of the bearing pins 47 and 48. Thus, for each revolution of the drive shaft 35 and, therefore, for each revolution of the crank arm 38, each bearing pin 47 and 48 will travel a total of 180 degrees or more within its arcuate channels 49 or 50.

The bearing pins 47 and 48 are respectively connected to identical can clamping assemblies 51 and 52. Each can clamping assembly comprises a center yoke 53, an end plate 54, a clamping plate 55, a pair of guide rods 56, and a clamping screw 57. Each center yoke 53 is provided with bearing pins 58 and 59. Each bearing pin 58 is mounted in the center race of a bearing assembly 60 and each bearing assembly 60 is mounted on the side frame member 21. Similarly, each bearing pin 59 is mounted in the center race of a bearing assembly 61 and each bearing assembly 61 is mounted on the side frame member 20.

Each center yoke 53 is further provided with a projecting member 62 which is fixed to each bearing pin 47 and 48. Each revolution of the drive shaft, therefore, drives the yoke through a total are travel of, for example, about 180 degrees, and each can clamping assembly 51 and 52 is pivoted about the axes of the bearing pins 58.

Each yoke 53 is provided with a pair of bores 62 within which the guide rods 56 are pinned. Each yoke 53 is also provided with a center bore 63 through which the clamping screw 57 extends. The clamping screw 57 is retained within the bore 63 by a pair of roll pins 64 which prevent axial movement of the clamping screw but which permit rotation of the same within the bore 63.

Each end plate 54 includes spaced bores 65 which slidably receive the guide rods 56. Each end plate 54 further includes a threaded, centrally disposed bore 66 through which one end of the clamping screw 57 is threaded. The clamping screw projects through the bore 66 and is provided with a crank handle 67.

The inner face of each end plate 54 is provided with a series of concentric depressions 70 designed to engage one end of any of a series of paint cans having different diameters.

Each clamping plate 55 has a fiat inner surface and a threaded pin 71 which projects outwardly from the outside surface of the clamping plate 55. Each clamping plate 55 is mounted on a plate support member 72 which carries a resilient bushing 73 in its upper end. The threaded pin 71 extends through the resilient bushing 73 and the threaded pin is retained in this position by a stop nut 74. The flexible bushing 73 permits non-axial movement of the threaded pin 71 for a purpose which will hereinafter become apparent.

Each support member 72 has a centrally disposed, threaded lower bore 75 through which the clamping screw 57 extends and a pair of lower guide bores 76 through which the guide rods 56 extend. The end of the clamping screw 57 which is threaded through the bore 75 is provided with a cap 77.

The clamping screw 57 is provided with left-hand threads on the portion which extends through the bore 66 in the end plate 54 and is provided with right-hand threads on the portion which extends through the bore 75 in the clamping plate 55 so that, upon clockwise rotation of the clamping screw 57 by the handle 67, the end plate 54 and the clamping plate 55 will be moved toward the yoke 53 in equal increments. Thus, a can may be clamped between the end plate 54 and the clamping plate 55 so that its center of gravity will be aligned with the center of rotation of each clamping device 51 and 52. Of course it should be appreciated that the center of gravity of a can need not necessarily be aligned with the center of oscillation of each clamping device 51 and 52 since departures from such alignment will still produce desired 7 turbulent flow according to this invention.

As was previously indicated, the center of rotation of each clamping device is defined by the axes of the bearing pins 58. When a container, such as a paint can 80 in the can clamping assembly 51, is engaged by the plate 54 and the clamping plate 55 and axial pressure is applied to such a container, the upper portion of each end plate 54 may tend to bend away from the end of the container. However, in such a situation, the end of the paint can remains seated in its recess 70, since the clamping plate 55 is permitted to flex by its bushing 73 so that the clamping plate 55 securely engages its end of the container.

With the motor turned on and with the crank arm 38 rotating in a clockwise direction, as viewed in FIGS. 1 and 2, the connecting rods 41 and 42 will cause the can clamping assemblies 51 and 52 to progressively assume the positions illustrated in FIGS. 6 through 9 during one revolution of the crank arm. Thus, as may be seen in FIG. 6, the bearing pin 47 has reached one end of the channel 49 so that the container 80 is tilted about its center of gravity at an angle of 45 degrees with respect to the horizontal. In this position, the bearing pin 47 has just completed its arcuate travel through the channel 49 and is at an instantaneous at-rest position with zero velocity and zero deceleration.

In the position of the parts illustrated in FIG. 6, a can 81 in the can clamping assembly 52 is in a horizontal position, since the bearing pin 48 is half-way through its downward travel in the channel 50. The can 81 at this instant is being rotated about its center of gravity in a clockwise direction and is at its peak acceleration and is about to decelerate as the bearing pin 48 thereafter approaches one end of the channel 50. Thus, it should be appreciated that when the bearing pin 48, and therefore the can 81, reaches its peak acceleration, the bearing pin 47 in the other can clamping assembly 51 has zero acceleration so that there is no added downward component of force caused by the container 80 in the latter assembly.

As may be seen in FIG. 7, the crank arm 38 has progressed 90 degrees in a clockwise direction from the position illustrated in FIG. 6. In this position of the parts, the bearing pin 47 is half-way through its arcuate travel in the channel 49 and is at its peak acceleration, and the can 80 is in a horizontal position and is being rotated in a clockwise direction about its center of gravity. At this time, the container 81 is in an at-rest position at an angle fluenced by any acceleration of theother container. of 45 degrees relative to the horizontal, and the bearing pin 48 has reached one end of the channel 50. Thus, the at-rest condition of the can 81 minimizes an upward force component caused by the can 80.

In FIG. 8, the crank arm has moved 90 degrees from the position illustrated in FIG. 7, and the bearing pin 47 has completed its upward travel in the channel 49, and the can 80 has completed its clockwise rotation about its center of gravity and is illustrated at rest at an angle of 45 degrees with respect to the horizontal. The bearing pin 48 is half-way through its upward travel in the channel 50 and has attained maximum acceleration. The container 81 is being rotated in a counterclockwise direction about its center of gravity.

In FIG. 9, the crank arm 38 has been rotated 90 degrees in a clockwise direction from the position illustrated in FIG. 8, and the container 80 has been rotated in a counterclockwise direction about, for example, its center of gravity and is illustrated in a horizontal position. The container 81 has attained the extent of its counterclockwise rotation and is about to begin its clockwise rotation.

One complete revolution of the crank arm is completed when the illustrated linkages once again attain the position illustrated in FIG. 6.

Each container 80 and 81 is subjected to rapid acceleration and deceleration through an arc of 90 degrees. Since the container is not smooth-walled about its axis of rotation, the rapid oscillations produce strong currents in the contained liquid to thereby violently agitate and mix the liquid.

It should be appreciated that the apparatus may be operated with a single clamped container and with the other clamping assembly unloaded. In fact, the intensity of vibrations in the machine does not depend on the operation of the apparatus with one or two containers, since peak acceleration of a single container is not in- The apparatus 10 further comprises a vertical mounting pipe 90 which is fixed at its upper end to the top plate 11. The bottom end of the pipe 90 is fixed to a bottom plate 91. Each end of the bottom plate 91 is fixed to a foot support strip 92., and each end of each strip 92 is provided with a vacuum cup 93. The pipe 90 is vertically aligned with the center of gravity of the mixing apparatus 10 so that upward and downward components of force during the operation of the machine are transmitted along the pipe 90 to the plate 91, the strips 92, and the cups 93. The bottom plate 91 and the strips 92 have a resonant frequency which is substantially greater than the basic system frequency during the operation of the mixing apparatus 10. This minimizes any tendency of the machine to walk during operation.

Guard covers 94 and 95 are hinged to the upper ends of the side frame members and 21 to minimize the possibility of snagging articles of clothing when the machine is in operation. Moreover, such guards may prevent paint spattering, which may be caused by a defectively sealed can. For ease of loading, the guards may be raised (FIG. 1, guard 95) and then lowered (guard 94) during the operation of the machine. As a safety feature, the guards may engaged a microswitch when they are in the down position to permit operation of the motor only when both guards are in the operating position.

The invention is not limited to the slavish imitation of each and every one of the details set forth above. Obviously, devices may be provided which change, eliminate, or add certain details without departing from the scope of the invention.

What is claimed is:

1. A method for mixing and agitating a liquid in a closed cylindrical container comprising oscillating said container repeatedly through an arc of at least about degrees about an axis passing through the container and its contents and perpendicular to the cylindrical axis of said container.

2. The method according toclaim 1 wherein said firstmentioned axis is horizontal and passes through the center of gravity of the container.

3. Apparatus for mixing liquids in containers comprising clamping means for engaging flat end walls of a cylindrical container, and means for oscillating said clamping means through an arc of at least about 90 degrees about an axis passing through the container and perpendicular to the cylindrical axis of the container.

4. Apparatus for mixing and agitating fluids in containers comprising a pair of clamping means for respectively retaining a pair of cylindrical containers, each of said clamping means being pivoted to a pair of spaced frame members of the machine, the pivotal connections between each of said clamping means and said frame members coinciding with oscillation axes passing through the centers of gravity of the respective containers and perpendicular to the cylindrical axes of the respective containers, and means to oscillate each clamping means about its axis of oscillation through an arc of at least about 90 degrees, said oscillating means oscillating one of said clamping means out of phase with respect to the other clamping means.

5. Apparatus according to claim 4 wherein each clamping means includes a yoke pivotally connected to said spaced frame members, a clamping screw extending through a portion of said yoke in a direction perpendicular to the oscillation axis of the clamping means, means for axially retaining said screw relative to said yoke but permitting rotation of the screw, said screw having oppositely threaded end portions, an end plate threadedly connected to one of said end portions, a clamping plate threadedly connected to the other end portion, whereby rotation of said screw in one direction will move said end plate and clamping plate toward each other in equal increments to clamp a cylindrical container therebetween and rotation of said screw in the opposite direction will release said container.

6. Apparatus according to claim 5 wherein one of said plates includes plate mounting means for retaining an inner face of said plate in a normal position perpendicular to the axis of said screw but permitting said plate to flex to a nonperpendicular position upon the application of unequal forces to the face of the plate.

7. Apparatus for mixing liquids in containers comprising clamping means for engaging flat end walls of a cylindrical container, means for oscillating said clamping means through an arc of at least about 90 degrees about an axis passing through the container, and perpendicular to the cylindrical axis of the container, said clamping means including a yoke having upper end portions pivotally mounted in side frame members of the machine, an arcuate channel in one of said side frame members and having its center at a point of pivotal connection between said yoke and said one side frame member, means 7 a 7 8 connected to said yoke and projecting through said chan- References Cited nel to guide said yoke in its clamping means through UNITED STATES PATENTS oscillations of at least about 90 degrees, and driving means 7 56 connected to said projecting means to oscillate said yoke 3281083 10/1885 'f about said pivotal connection. 5 2,034,902 3/1936 Hemze g 8. Agitating apparatus according to claim 7 wherein 5 322 3x :(Orgcnson a I said driving means comprises a connecting rod pivotally 9 0 0st 2 2,599,833 6/1952 Holm'lund 259-72 connected at one end to said PI'OJCCilIlg means and pivtal-l connected at its ther nd to a r nk arm in a s for 2717700 9/1955 Gruzensky et 259-45 X y 6 c a e 2,735,663 2/1956 Holt 259-75 rotating said crank arm to drive said projecting means 10 within its channel through said are. ROBERT W. JENKINS, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,388,895 June 18, 1968 Axel E. Ogren et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as' shown below:

Column 5, line 18, cancel "fluenced by any acceleration of the other container." line 55, after "in-" insert fluenced by any acceleration of the other container.

Signed and sealed this 4th day of November 1969.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer 

